Visual Studio does not throw a warning during build for events marked Obsolete

  • Article

This article describes the issue where Microsoft Visual Studio doesn't throw a warning during build for events marked Obsolete.

Original product version:   Visual Studio Professional 2010, Visual Studio Premium 2012
Original KB number:   2832705

Symptoms

You have a C# Class library project with a class containing an event and you marked the event with the Obsolete attribute. When you add reference to this class library in other project, for example a Console application and subscribe to that event, no warning is generated in the latter project.

Typically a warning CS0618 should be generated during compilation in Visual Studio when a method, event or property is marked with the Obsolete attribute.

Obsolete attribute is applicable to all program elements except assemblies, modules, parameters or return values and works as expected.

Cause

This is a known issue with C# compiler.

Status

This issue is observed in all editions of Visual Studio.